Magnetic core plane threading machine and method



Feb. 25, 1964 J. F. MARINE ETAL 3,122,173

MAGNETIC CORE PLANE THREADING MACHINE AND METHOD Filed April 13, 1962 6 Sheets-Sheet 1 FIG. 2

INVENTORS JOHN F. MARiNE BY ROBERT T. SHEVLIN @Xwy,

Feb. 25, 1964 J. F. MARINE ETAL 3,122,178

MAGNETIC CORE PLANE THREADING MACHINE AND METHOD Filed April 13, 1962 s Sheets-Sheet 2 IN VEN TORS JOHN F. MARINE BY ROBERT T. SHEVUN Feb. 25, 1964 J. F. MARINE ETAL 3, 7

MAGNETIC CORE PLANE THREADING MACHINE AND METHOD Filed April 13, 1962 6 Sheets-Sheet 3 FIG. 6

INV EN TORS JOHN F. MARINE BY ROBERT T. SHEVLIN FlG.8 4%,

Feb. 25, 1964 J. F. MARINE ETAL 3,122,178

MAGNETIC CORE PLANE THREADING MACHINE AND METHOD Filed April 13, 1962 6 Sheets-Sheet 4 cu m Q 7 INVENTORS JOHN F. MARINE z1 BY ROBERT T. SHEVLIN Feb. 25, 1964 J. F. MARINE ETAL MAGNETIC CORE PLANE THREADING MACHINE AND METHOD 6 Sheets-Sheet 5 Filed April 15, 1962 FIG.l|

INVENTORS JOHN F. MARINE ROBERT T. SHEVLIN 4 W 3 l 4 4 5 B 8 4V. Mk 2 M z 2 85 7 2 w M 2 mm m F 2 3 2 Feb. 25, 1964 J. F. MARINE ETAL 3,122,

MAGNETIC CORE PLANE THREADING MACHINE AND METHOD Filed April 13, 1962 6 Sheets-Sheet 6 INVENTORS JOHN F. MARINE BY ROBERT T. SHEVLIN United States Patent imnl 3,322,378 MAGNETEC CQRE ?L.la THFEADENG MA Ci-HNE AND hEETHDD John Ferre lid'arhre, Yew York, and Robert T. Sheviin,

Kew Gardens, NFL, assignors to he United States of America as represented by the United States Atomic Energy Commission Fiied Apr. 13, 1962, Ser. No. 187,i48 7 (Cl. 14t3-93) The present invention relates to a magnetic core plane threading machine and, more particularly, to apparatus for threading magnetic cores for word-organized memories used in high-speed, general purpose digital computers.

In a typical memory core used for digital computers, ferrite toroidal cores are fixed in a staggered, three dimensional pattern which requires that substantially all wiring of the cores be accomplished by laborious, hand methods.

In order to simplify the wiring problem somewhat, it has been proposed, with successful results, to fix the ferrite cores in a lattice array formed by layers of planes. In one particular arrangement, this is accomplished by pre-assembling the ferrite cores in flat plastic boards that fix their geometry. The board thickness holding the cores is the same as that of the cores to obtain a flat unit easy to handle. Holes in the board are of the same diameter as the outside diameter of the cores, and the cores are then inserted into the holes and held in place with an adhesive spray or a cellophane overlay which is punctured during subsequent wiring or threading of the cores. The ferrite cores are wired in quadrature by hand, as in the case of the previously mentioned core array.

The cost of core memories of this type for use in large computers frequently runs to about forty percent of the cost of the whole computer. To give an example of the magnitude of the threading, or interlacing job involved in such memory systems, a recently constructed general-purpose computer having a memory system with 450,000 cores had to be interlaced with three and four electrical conductors each. This was done by hand with the result that not only was a very high percentage of the total cost of the computer due to this hand operation, it additionally represented a very substantial time element in the construction of this machine.

The present invention concerns a method and threading device which mechanically and automatically interlaces ferrite cores placed in a flat array as described above and hence, avoids much of the time and cost involved in the hand-wiring techniques generally in use. In accordance with this invention, there is provided for carrying out mechanically and automatically the threading of the cores, arranged as described, by a pair of reciprocating hooks between which the plane of the cores is situated. A pair of needles reciprocate to transfer a length of conductor or wire through each core while the aforementioned hooks reciprocate in order to engage with the condoctor to thread the needles. At the beginning of each row of cores, the operation as described begins with a length of conductor suflicient to thread the whole row of cores. The needles and hooks cooperate in a unique fashion to transfer the loose end of the conductor up through one core and down through the next core until the whole row is completed and the conductor is exhausted.

It is, therefore, a first object of this invention to provide apparatus and a method for threading mechanically and automatically with conductors portions of the memory system of a digital computer.

It is still another object of this invention to provide a 3,i22,l78 Fatented Feb. 25, 1934 ice machine for automatically threading a row of hollow members.

Another object is to provide apparatus and method for interlacing with thread a series of spaced members.

Still another object of this invention is to prepare automatically and mechanically magnetic cores for wordorganized memories used in digital computers.

Other objects and advantages of this invention will hereinafter become more evident from the following description of preferred embodiments of this invention taken with the accompanying drawings in which:

FIG. 1 is a portion of plastic board with ferrite cores mounted therein suitable for application of this invention;

FIG. 2 is a schematic illustration of the core array and Wiring;

FIG. 3 is a schematic illustration of a threading subassembly in accordance with this invention;

FIGS. 4 and 5 show details of the needles and hooks as utilized in FIG. 3;

FIG. 6 shows an alternate needle shape;

FIG. 7 is an isometric view of the cylinder and head assembly suitable for use with the sub-assembly shown in FIG. 3;

FIG. 8 is a more detailed isometric view of a head illustrated in FIG. 7;

:FIG. 9 is an isometric view of a modified version of the invention assembled on a frame for operation;

FIG. 9a is an isometric view showing details of a modified head illustrated in FIG. 9;

FIG. 9b is a detail of a portion of the drive for a hook rod;

FIG. 10 is a detail of FIG. 9;

FIGS. 11 and 12 illustrate the operation of the detail shown in FIG. 10; and

FIG. 13 is a schematic of a suitable electrical drive for use with the device of FIG. 9.

Referring to FIG. 1, wherein there is shown a portion of a that plastic board 12 with ferrite cores 14- pre-assembled therein, the thickness of board 12 may be substantially the same as that of ferrite cores 14. In assembling cores 14 into board 12, holes of the same diameter as the outside diameter of cores 14 are drilled or punched and cores 14- are then inserted into the holes and held in place with an adhesive spray or a thin plastic or cellophane overlay which is penetrated readily during the threading process. Core board 12 with ferrite cores 14 mounted therein are Wired in accordance with this invention by threading two twisted pairs of magnetic wires as shown in FIG. 2 which schematically illustrates the core array and wiring. As is understood in the art, the magnetic wire is a conductive wire (or conductor) with a thin insulating coating which is sprayed or dipped on. In connection with a particular ferrite core 14A shown in FIG. 2 there are shown two pairs of twisted wires 16, 18 and 22, 24 threaded therethrough to illustrate the details of a typical wiring arrangement which may be obtained by the instant invention.

Referring to FIG. 3, there is illustrated a threading subassembly 25 consisting of a pair of oppositely facing elongated, hollow cylinders 26 and 28, and a second pair of spaced hollow cylinders 32 and 34, which are parallel to each other and which terminate adjacent the ends of cylinders 26 and 28, respectively, as illustrated. The axes of cylinders 26, 28, 32 and 34, are all in the same plane for the embodiment illustrated. Cylinders 26 and 28 are designated the needle cylinders or tubes while cylinders 32 and 34- are designated the hook cylinders or tubes. Located within needle tubes 26 and 28 are solid slidable pistons 36 and 38, respectively, which have embedded in their facing ends a pair of needles or needle members 42 and 44, respectively, as illustrated. In similar fashion located within hook tubes 32 and 34 are a pair of hook bearing solid pistons 46 and 48 which have embedded in their ends facing tubes 26 and 2S, hooks or book members 52 and 54, respectively. More complete details of needles 4-2 and 44 are shown in FIG. 4 While those of hooks 52 and 54 are shown in FIG. 5. As shown in FIG. 4, needle 42 is constructed of a. thin metal material such as tension steel spring wire formed into a thornbic or other suitable shape so that when the'ends are mountedin piston 36 as illustrated under proper operating conditions. the expanded sides may be squeezed together. Needle 44 not shown in FIG. 4 is identical to that of 42 and both needle assemblies contained within tubes 26 and 28 are identical. An alternate construction, a needle 42a, is illustrated in FIG. 6.

In FIG. 5.it is seen that hook S2 is actually an assembly consisting of a pair of hook elements 52a and 52b embedded at one end in an end face of piston 46. Elements 52a and 52b extend parallel to each other and terminate in free hooked ends with.their points just barely touching as illustrated. The material making up hook 52 may also be tension steel spring wire. Hook 54 within tube 34 is identical to hook 52 located-within tube 32.

In order properly to orient sub-assembly as shown in FIG. 3.there is shown inphantom a side view of board i2. As will beevident from-the description of needle 42, the latter penetrates the particular ferrite core lined up with the axis of cylinders 3'6 and 38. A more complete description of the mode of operation and the furictionfl relationship between needles 42 and 44 and hooks 52 and 54 will follow fuitherbelow;

7 Regarding the lengths. of tubes 26, 28, 32 and 34, and

their associated rods, it should be immediately pointed out. thatthey should be such that each tube will be able to contain during translation of its respective rod, the latter fully retracted and the conductor fully extended in a length suflicientto thread a complete row of cores 14.

In order to thread cores 14, one row at a time, it is necessary to secure board 12 and to translate the latter in its plane by discrete amounts equal to the distances between core centers along a plane perpendicular to the plane of the cylinders described above. For this purpose there is provided a head assembly 55 which is illustratedaiong with portions of sub-assembly 25 in FIG. 7. There it will be seen that a pair of supportingheads 54-and 56 are located to support the endportions' of cylinders 26, 28, 32 and 34. Head 54 consists of a pair or" L- shaped members 57 and 53. Asseen in connectionwith cylinder 26, the latter passes through member 57 and terminates. justinside thereof. The other cylinders are similarly mounted. It will be also noted from FIG. 7 that core board i2 is located between the heads 54 and 5e as described in connection with FIG. 3. The view in FIG. 7 is takenfrom below to show details since cylinders 26, 28, 32 and 34-wou1d be mounted ina horizontal plane and board 12'would be in a vertical plane for best results as will be later understood more clearly.

The second pair of members 61 and 62 similar in shape to members 57 and 5'8 are mounted as illustrated to provide essentially a surface area betweenthe two opposite head portions of head assembly 55"through which board 12 passes. It will be noted that members 5'8 and 62 have a pair of legs 64 and 66 facing each other in which there are provided a pair of slots 68 and 72, respectively,

whichare provided with enlarged openings-or holes 74 and 76.. Holes Hand 76 pass completelythrough legs 64 and (:6, respectively, and areon an axis which is perpendicular to board 12 and passes through the center of the particular core which is being threaded at the particular instant. The spacing between the facing surfaces of legs 64 and 66 is such as to sandwich-in board l2 but leave the latter free to be moved. Holes 7- and 76 preferably each'have the same diameter as the inside diameter of'the particular cores which are being threaded.

As already noted, holes 74 and 76 are aligned with each other and with the particular core being threaded i and further with the path of needles 42 and 44 illustrated in FIG. 3.

To complete the description of each head 5e and 56, reference is made to member 53, also shown in FIG. 8, which is provided with a pair of flat parallel inserts 79 arid 82 which extend from the wall of member 53 not quite reaching an extension of cylinder 26. These inserts 79and 82 perform a function in connection with the threading operation which will be described further below. in addition, a pair of wires 84 and 86 extend vertically out from member 58, reaching across an extension of cylinder 26. Guiding Wires 8 and as are parallel to each other and in a plane parallel to board 12. The spacing of inserts 79 and 82 from each other is critical as will become evident from the description further below.

In similar fashion, head 56 is provided with a pair of flat inserts 8-8 and 92, and a pair of guiding wires 4 and 96. spaced apart with the mid-point between them aligned with the axis of cylinder 32, and inserts 88 and 92 are similarly disposed with respect to cylinder 34. i

The apparatus as described in connection with H65. 2 through 7 has been somewhat schematized in order to simplify the description of its operation which follows. It'will be noted in FIG. 7 that an arrow A indicates the movement of core board 12, so that, for example, cores 14 in the row designated B-B will be threaded one at a time. To thread row BB core board 12 is placed in the space separating heads 54 and se as shown with end core 14b in row B-B aligned with holes 74 and 76. In FIG. 7, board 12 has already progressed part of the way along row BB. As FIG. 7 does not show the rods and their supported needles and hooks it will be necessary to refer to FIG. 3 simultaneously to understand the steps in this procedure.

A- length of conductor 73 sufiicient to interlace all'ofv row BB is attached at one end to board 12 at some convenient-point C beyond the end of the row, and the free end is held extended away fromboard 12, as shown in FIG. 3. Rod 38 is moved'toward board 12 until its needle 44 penetrates successively hole 76 in head' 55, core 14b, and emerges through hole 74 in head 54. As needle 44 passes through these holes it is squeezed, but as it comes out through holes 74 and member 58 it resumes its normal rhombic shape. At this point needle 44 comes to rest in the traveling path of'hook 52 of rod ifi.

Hook 52 isthen translated toward head 54 passing through needle 44 and grasping a portion of conductor 78. Inserts 79 and 82 are spaced apart sufiicient distance and are located so as to separate the hook ele ments comprising hook member 52 so that the latter will grasp conductor 73 readily. Piston 45 isthen Withdrawn so that conductor 78' is pulled through slot 63 in head 54, through the eye of loop of needle tdand into cylinder 32. The other end of conductor 78 is heldfast by its attachmentat C to board 12 and thus extends through needle 44 and into tube 32. Then piston rod 38 with conductor 78 passing through the loop-of needledd is displaced away from board 12 into a fully retracted position in cylinder 28. Conductor 78 thus loops and slips through needle 44 as needle 44 pulls the former through core 14b into cylinder 23, so that when rod'38' becomes fully retracted the free end'of conductor 78 slips out of needle 44, and is fully extended without any loops within'cylinder 28. Therefore, cylinder 28 must be of sufficient length to accommodate the whole initial length of conductor 78which at the point just described extends from point C on board 12 through core 1% into tube 28.

Core board 12 is now translated in the direction of arrow A so that the second core in row 13-3 is aligned with holes 74 and 76 of the heads. and the travelingpath of needles 42 and 44; and conductor 78 is moved out of It should bepointed out that inserts 7% and 82 are hole 76 a small distance down slot 72, for a reason to be later described.

Needle 42 on rod 36 is then advanced through the then aligned core in board 12. Needle 42 penetrates hole 74, head 54, the core, and emerges through hole 76 into head 56. At this point, conductor 78 is in line with the loop of the needle 42, and is also in the traveling path or" book 54 on piston rod 48. Hook 54 is displaced toward head as, passes through the loop of needle 42, is opened by inserts 8S and 92, and grasps conductors 78. Because conductor '78 is located out of hole 76 down slot 72, needle 42 is between conductor '78 and hook 54 when the former passes through hole 76.

Rod 43 is then retracted away from head 56, pulling conductor 7-8 through the loop of needle Conductor is thus pulled out of cylinder 34 until it is fully extended. Rod 36 is retracted, drawing conductor 78 into cylinder 26 which is of sufficient length to hold the former as in cylinder 28. Board 12 is then advanced until the next core in the row is aligned with holes 7 3 and 7-5.

Guiding wires 84, 85 and 94, 96, perform the function of maintaining or holding conductor 73 within the clasping paths of the various hooks. Inserts 79, 82, and 83, 92, as already noted, restrain conductor 73 as it is first pushed by the hooks and contact the latter so that the hook elements are forced to open slightly to more readily grasp the conductor. While not shown, it is understood that guides or slots in the various cylinders and rods would be utilized to maintain rods 36 and 33 so that the openings in needles 4-2 and 44 always face cylinders 32 and 34, and the widths of hooks 52 and are always transverse to the length of conductor 7% To thread the rest of the cores in row B-B the process as described above is repeated, and would, of course, be used also to thread any of the rows other than row B described as well as the rows of cores turned 90 from row BB shown in FIG. 7.

it is understood that the arrangement just described may be assembled together as illustrated and the needles and hooks manipulated by hand to thread each row faster than can be done by hand alone. Stops may be used as understood in the art if desired to limit the movements of the various elements or may be controlled by the operator alone. In order to speed up the operation of the assembl a motor drive for each movable element may be provided as is well understood in the art, and an observer-operator may be utilized to energize each element by the use of an appropriate switch depending on observation to determine when each step is completed.

In FIG. 9 is shown a frame for supporting a modilied threading apparatus as described above. A central or main upper channel lltl is supported in a horizontal plane by a lower chnnel and a plurality of supporting angles generally designated Upper channel 110 is provided with an elongated pening 136 extendsuthcient length to accommodate core board ii in a vertical position for movement in the direction along the of slot 116. Thus slot 116 would be about twice the length of board 12.

A pair of angles 118 and 322 are mounted to form an overall cruciform configuration of frame One fiat surface of each of angles 11S and 122. is in the same plane as the top surface of upper channel 118. Angles and 122. are supported by vertically disposed angles 124 and a pair of bottom angles 12s and 128. A pair of members 13?. and 134 interconnecting the upper main I lit with upper side angles 113 and 2 2 by either g or bolting makes frame 19% into a very rigid structure maintaining the up er surfaces of channel ill) and angles 3.18 and 122 in a sin le horizontal plane.

The various pistons and rods of this invention to be now described are located on the upper surfaces of channel and angles 118 and 122 and are supported by lid.

slot 0 blocks having holes to accommodate the tubes or cylinders. For example, cylinder 34 is supported rigidly by a pair of blocks 136 and 13% mounted on channel 119 while piston d3 slidable within tube 34 is supported slidably by a pair of blocks 14' and 1 14 as illustrated. The o r cylinders and tubes are designated to correspond with the same elements in FIG. 3. Tube 32 and rod 46 are supported by blocks 136', 138', 142' and 144'. Tube 23 and rod 33 a e supponed by blocks 136", 133', 14-2 and 1 2-4". Tube 25 and rod 36 are supported by blocks 1353" (not seen), 133", 142" and 144".

A pair of heads and i413, differing somewhat from heads 5% and 56 in FIG. 7, are util zed where illustrated. Details of heads 1 6 and 143, are found in EEG. 9a. It will be seen that head has an outer rounded or conical surface facing head 143 and has penetrated theret gh at -e apex a hole 152 (performing the same function as holes 74 and '76 described in FIG. 3) and a radial slot extending in a hor zontal plane which allows for convenient loading the core plane initially with w re and other purposes as will be later seen. Hole 35?. is same or slightly smaller than the inside diameter of the particular cores to be threaded. Head 148 is identical to (but mirror image of) head M6.

The drive system for rods 36, 3-8, 4:5 and '3, is also illustrated in FIG. 9. There it will be seen that the drive system for rod consists of a DC. electric motor 1 2 supported one side of a plate 164, a pulley wheel res connected di tly to motor 262 and a pulley wheel 16S mounted on a plate 52.0 driven through belt 172 from pulley wheel An idler pulley wheel 176 is mounted adjacent block 1355 supported by a plate 177, and a string 1'73 connects pulley wheels 174 and 176. The string 73 is d at some convenient point to a screw or catch 179 extendin. from rod db for a direct, reciprocal drive as shown in the detail of FIG. 9b. By reversing current flow to motor 162 with a suitable switch, rod r ay be driven forward or backward at a rapid rate of erl. Pin l7? moves between plates and which, hence act as stops for the movement of rod 46. String 1'73 over pulley 17 iacts as a slip clutch for this purpose, or if desired, a slip clutch between plate 1-59 and pulley 174 may be used. Rod

seen) while rods 3-6 a Liv-311 by a sh ilar motor and drive assembly (not d are driven by similar motors and their drive arrangements (not seen).

along one t eof is a transport assembly 131 e in configuration and has a movable carthrough worms 1% and 1%, respectrvely desired. The bottom of carriage 132 is provide u a shoul er 1% which has a pair of pins 194 and 396 to which would be attached core board 12. Carriage -old board Z12 which extends through slot lid in upper rarinel and maintains board 12 in a vertical orientation and moves it in increments in the direction of arrow B. At beginning or" each row of cores to be threaded, carriage lSZ is up at the right end of assem ly it}? (as disposed in HS. 9) and after each core is tneaded board 12 is moved in the direction of arrow B so that the next core is aligned between heads 14-6 and '"ransport assembly 1313 may be manually cranked or motor driven to index carriage 152 to its next position for visual alignment, or some automatic drive and control using spaced micro switches may be used, as to be later briefly described. it will be seen that after a particular row of cores is threaded core board 12 would be unclamped from carriage 152 and moved down or up to the next row and carriage 3182 moved back to the b ginning of the row. It is understood that an electric motor, as later described, similar to the other electric motors desc i ed may be ut lized to move carriage 182 in accordance with the process conducted.

A refinement in the head arranger rent for increasing the speed of the threading operation is shown schematically in FlG. 9 represented by a pair of units 216 and 212 adjacent head 1%. A similar set of units El i and 216' are shown mounted adjacent head 1 5 5. The details of this arrangement are given in FIG. 10 in connection with units 23% and 212-.

' Referring to FIG. 10 it will be seen that units 21% and 212 are hollow boxes mounted on a plate 214. Unit 216 supports flat finger holding members 222 and 224 which are pivoted about pins 2 2% and 232. Unit 212 contains a solenoid 22s to actuate members 222 and 224 as will be later seen. A spring member 234 interconnects members 222 and 224 to bias them in the direction of separating them as in EEG. 11. Two pair of wire holding fingers 242 and 2d4 extend from members 222 and 224- for a purpose to be later described. n the other side of pins 228 and 232 is the conical end 236 of a shaft 238 which extends through the end wall of unit 213* into unit 212 and terminates in solenoid There it is seen that when solenoid 226 is energized shaft 238 is moved to the left as indicated by arrow C in FIG. 12 so that conical end 22-6 of shaft 23-8 tends to pivot fingers 242 and 244 together. When solenoid 226 is de-energiz d shaft 238 is moved to the right as indicated by arrow B in FIG. ll, permitting spring 23 to separate fingers 242 and 244. The effect of this arrangement is to hold conductor 73 aligned with the axis of rod 48 holding hook 54 in cylinder 34 advancing to grab conductor 78 as shown in FIG. 12.

The operation of this assembly just described to hold conductor 78 in place falls into the overall sequence of operation of the apparatus in the following way. During the period of time when conductor 78 is fully extended into needle containing cylinder 28 (as in FIG. 10), needle 42 will advance through heads 146 and 14S and stop between conductor 73 and hook 54. The latter advances through the inside of needle 42 and grabs conductor 78 to then pull the latter back through needle 42 into cylinder 34. At the time when needle 42 begins its advance through heads 14% and 14S, solenoid 226 is energized so that fingers 242 and 244 will clamp conductor 7 8 in place (as in FIG. 12) to permit the latter to be aligned with hook 54 and needle 42. When hook 54 has grabbed conductor 78, or if desired, when hook is retracted, solenoid 226 is de-energized to retract fingers 242 and 244.

It will be seen in FIGS. 11 and 12 that conductor '78 is in slot 154 oif to the left of hole 152'. This displacement insures that when needle 4-2; advances from hole 152" it will be then between conductor 78 and hook 54. Movement of conductor 7% out of hole 152' to permit needle 42 to pass through unopposed is brought about (as previously explained) by the indexing of board 12 which moves in the direction of arrow B after conductor 78 is pulled into cylinder 28 by needle 44 as shown in FIG. 10.

It should be apparent that the wire holding assembly just described forms an additional function in the operation of. this apparatus. At the beginning of each row or cores, it was earlier pointed out that the end of conductor 78 is attached to some point opposite the first core of the 7 row to be threaded. In order to begin threading the row,

conductor 7 8 is pulled through the slots in heads 14s and 148, and solenoid 226 is energized so that fingers 242. and 24 will hold conductor 73 in position for the start of the threading operation.

In the operation of the apparatus shown in FIG. 9, the various electric motors described may be energized in the manner illustrated in FIG. 13. It will be seen that motors 162, 162', 16 and 162" are provided with double pole switches SW1, SW-Z, SW3- and SW 5 respectively, each having forward (F) and reverse (R) drives for their respective motors. There is also provided a motor 362 which is energized by a switch SW-S to advance carriage 182 from core to core between threading steps. The cores may be aligned visually or by a pointer extending from carriage 332 to a cross member 133 which would he provided with calibrations spaced identically with the cores. An electrical source El provides the power for the various motors. A power switch (not shown) between El and switches would be used to cut off power to the machine when not in use. An operator would be provided with a program chart and would operate the switches in accordance with the program.

if desired, the whole operation may be made automatic by using either limit or light sensitive switches to sequence the various operations.

While only preferred embodiments of this invention have been described, it should be understood that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

Vie claim:

1. A magnetic core plane threading machine for interlacing with a flexible conductor a row of spaced, hollow elements mounted in a flat board, comprising, in combination, means for transferring a sufiicient length of said.

conductor to interlace the whole said row back and forth through said board, and means for advancing said board along said row to permit said conductor to be passed back and forth through successive hollow elements in said row, said transferring means including a pair of needle means for making the actual transfer of said conductor through said elements and hook means for each of said needle means for threading a needle means to permit the latter to make the aforesaid transfer.

2. The threading machine of claim 1 in which means are provided to hold said conductor in proper position for each of said hook means to engage said conductor prior to threading a needle means.

3. The threading machine of claim 2 in which each of said needle means, hook means, and board advancing means is provided with an independent drive arrangement to permit all of the operations to be adjusted for proper, sequential operation.

4. A magnetic core plane threading machine for interlacing with a flexible conductora row of spaced, hollow elements mounted in a fiat board, comprising, in combination, a pair of spaced threading heads having formed therein facing needle holes, means for supporting said board between said heads and for aligning a hollow element with said holes, a pair of oppositely facing first and second needle means aligned with said holes on opposite sides of said first and second heads, respectively, each of said needle means having a loop member at the end thereof facing its respective head, a pair of parallel first and second elongated hook means on opposite sides of said board parallel to the plane of said board and in a common plane with said needle means, said hook means each terminating in a hook member and axially slidable for moving each of said hook members across the path of said needlemeans and away from said heads, said first needle means being axially reciprocal in advancing its loop memher through said holes and aligned hollow member coming to rest along the axis of said second hook means, said second hook member advancing through said first needle loop member to engage a portion of said conductor, which is extending from said board, through at least said second head hole, said second book member being withdrawn to draw said conductor back through said first needle loop member, said first needle member being then retracted to draw said conductor back through said holes and aligned hollow member until said conductor extends its full length along the axis of said first needle means away from said first head, said board being then advanced until the next hollow member is aligned with said holes, and said second needle loop member is advanced through said holes and next hollow member up to alignment with the axis of said first hook means to repeat the sequence as aforesaid, thereby alternating between said first and second needle means to transfer said conductor back and I forth between successive hollow members to interlace an entire row of hollow members With said conductor.

5. The threading machine or" claim 4 in which said heads are provided with slots extending from said holes in the plane of said needle and hook rneans away from said hook means, and said board is advanced in the same direction as said slots extend from said holes, with the result that as each hollow element is advanced, said conductor will be moved out of said holes into said slots to permit said needle loop members to move between said conductor and the hook members thereby insuring proper threading of said needle loop members.

6. The threading machine of claim 5 in which means are provided to clamp said conductor in place properly aligned with said hook means prior to engagement by the latter.

7. A method of interlacing with a flexible conductor a row of spaced, hollow elements mounted in a flat board, comprising, the steps of attaching one end of said conductor of sufiicient length to interlace the Whole said row to a point on said board at the beginning of said row, passing a first needle through the first element in said row to the side of said board to which said conductor is attached, threading said needle With the free end of said conductor, withdrawing said needle back through the first said element trereby pulling through said conductor until the latter is fully extended, advancing said board a distan-2e equal to the spacing between elements in said row, passing a second needle through the second element in said row to the side where the free end of said conductor is extended, threading said second needle with the free end of said conductor, Withdrawing said second needle bacl through said second element thereby pulling through said conductor until the latter is fully extended, advancing said board to the third saidclement, and repeating the aforesaid steps until tie whole row of elements is interlaced by said conductor.

References Cited in the file of this patent UNITED STATES PATENTS 1,485,827 Bull Mar. 4, 1924 2,191,647 Edge Feb. 27, 1940 2,325,461 Arthur July 27, 1943 2,420,512 VJoller May 13, 1947 

1. A MAGNETIC CORE PLANE THREADING MACHINE FOR INTERLACING WITH A FLEXIBLE CONDUCTOR A ROW OF SPACED, HOLLOW ELEMENTS MOUNTED IN A FLAT BOARD, COMPRISING, IN COMBINATION, MEANS FOR TRANSFERRING A SUFFICIENT LENGTH OF SAID CONDUCTOR TO INTERLACE THE WHOLE SAID ROW BACK AND FORTH THROUGH SAID BOARD, AND MEANS FOR ADVANCING SAID BOARD ALONG SAID ROW TO PERMIT SAID CONDUCTOR TO BE PASSED BACK 